Personal communication service (PCS) is a service in which subscribers, rather than locations or telephone stations, are assigned a personal telephone number. Calls placed to a subscriber's personal telephone number are routed to the subscriber at a telephone near that subscriber's current location. In order to provide a subscriber with such a personal communication service, e.g., as disclosed in U.S. Pat. No. 4,313,035, issued to Jordan, et al., the system providing the service (PCS system) must be supplied with the telephone number of a telephone near the subscriber's current location to which it should route calls to his personal telephone number. Each time the subscriber changes his location, the telephone number to which calls placed to his personal telephone number are routed must be changed. This requires the subscriber to call into the PCS system and to supply the telephone number to which his calls should currently be routed. Constantly having to call in to the PCS system can be tiresome, and supplying a ten-digit telephone number each time a subscriber changes his location is cumbersome.
To overcome these drawbacks, one prior art solution is to program a scheduled sequence of telephone numbers at which the personal telephone service subscriber can be reached over a period of time. When a call is made to the subscriber, the PCS system picks the specific number in the sequence that is appropriate for the call and routes the call to that destination. In order to administer the sequence, the subscriber places a call to a live attendant. The live attendant collects the telephone numbers to which calls to the subscriber's personal telephone number should be routed, along with the corresponding time schedule, and enters this information into the PCS system by way of a computer-like terminal. This solution suffers from the disadvantages of being costly and of discouraging the owner of the personal telephone number from calling, because the interaction with the live attendant takes a relatively large amount of time.
Another prior art approach is to straightforwardly automate the functions of the live attendant. However, doing so requires a person who is administering a personal telephone number to supply, receive, and keep track of an unwieldy quantity of telephone numbers, each being, typically, a minimum of ten-digits in length. Such an implementation often results in confusion and is difficult to use. Even if shortened codes are assigned to each telephone number, the subscriber tends to quickly lose track of the telephone numbers assigned to each code, and hence loses the meaning of the code.